Filter and method of making



2, 1960 w. KASTEN 2,947,419

FILTER AND METHOD OF MAKING 2 Sheets-Sheet 1 Filed May 26, 1955 m m w m WALTER KASTEN Aug. 2, 1960 w. KASTEN FILTER AND METHOD OF MAKING 2 Shee'LS -Sheet 2 Fil ed May 26, 1955 WALTER KASTEN A TTORVNEY.

Unite 12 Claims. (Cl. 210-435) The present invention relates to filters and more particularly to a material-and a'combination of materials for filter and/ordemulsifying elements and to a method of making said elements.

One of the principal objects of the present mventron is to provide a filter structure utilizing material CSPBCIEL 1y adapted for impingement type filtration, which can be repeatedly cleaned without appreciably decreasing its filtering capacity and whichretains its shape and structure in both the filtration and cleaning operations.

Another object of the invention is to provide a compound filter element in which one type or size of foreign material "is removed by one element and another type orsize of foreignmaterial is-removed by another element.

Another object is to provide a method of making the aforesaid elements for use in either filter or demulsifying operations.

Other objects and advantages will become apparent from thefollowing description and accompanying drawings, wherein:

Figure 1 is a vertical cross-sectional view through a filtering device adapted tofilter air;

Figure 2 is a vertical cross-sectional View through a filtering and demulsifyingdevice in which an element embodying the present invention is used;

Figure 3 is a sectional view taken along line 33'of Figure 2;

Figure 4 is a perspective view of a layer of nylonresin material one side of which is smooth and the other :side of which is fuzzy; and

Figure 5 is a diagrammatic view showing a means of splitting a nylon-resin sheet of material to form a layer having the characteristics shownin Figure 4.

Referring more specifically to the drawings -and to Figure 1 in particular, a compound filter element is center of deflector 16. A winged nut 20 is provided on the deflector end of the stem so that the unit can be readily disassembled for cleaning. When the filtering device is assembled the end of the deflector closes one end of the filter element and the base closes the other end except 'for a port 22 which connects the interior of the'element with the passage leading into the reservoir aldehyde condensation product. treated with "thismateri-al have been formed, they are or thelike. Aconical screen 24 forms a drainage chamber to connect the filter element with port 22.

sists of a plurality of washer-like layers, either as individual layers or as convolutions of a helically Wound unit, having radial pores between each layer to provide passages for the fluid being filtered. The layers of the 'filter element'may be of a fibrous material held together by a discontinueusbond so distributed that radial pores are formed between the layers at frequent intervals. The discontinuity of the bond may be controlled by using a paper or fibrous material having a predetermined rugosity on both surfaces thereof'so that the valleys of therugosities form 'the passages, and the peaks thereof form the 'poi-ntsof contact between the'adjacent layers.

The paper or fibrous material is preferably treated with a thermosetting resinous material such as phenolic form- After the elements heated to a temperature and for a time sufficient to cause the resinousmaterial to set, making the material forming the elements but not the elements themselves,

substantially impervious to fluid, the pores between the layers remaining open after the treatment. The foregoing filter element and amethod of making the element are covered by my United States Patent No. 2,421,704, dated June 3, 1947.

The inner element 32 is composed of a mass of nylon fiberstreated with a thermosetting resin which bonds thefibers together at their points of contact so that the material so-formedretains its structure and shape during operationofthe filter and in cleaning. The inner element shown in Figure .1 consists ota plurality of washer-like layers cut from a'fi-at sheet of the nylon fibrous material treated withthe resinous material and stacked on stem 18. This material is particularly suitable for use undersevere operating conditions, since the nylon fibers are resistant to abrasion by solid particles and corrosion by many chemicals such as 'alkalis, organic acids and common solvents such as carbon disulfide, The

distortion. The density can be varied to suit requirementsas. to the size of the particles to be removed from .the fluid. To clean the element, nut 20 and deflector 16 'are' removed from stemrl8 and the element is lifted from the stemnand base. Inner and outer elements are separated and cleaned independently. Since thewashers of the inner element retain their shape they can be separated into individual layers and washed in a suitable solvent and then reassembled in the outer element.

The filtering and demulsifying device shown in Figures 2 and 3 consists 'of an internal chamber 40 in which is mountedan element 4-2 embodying the present inven- .tion and an external chamber 44 in Which are mounted a plurality of filter elements 46 which may be either e'dge type orpleated elements, the two chambers being connected by a port 47. The fluid to be purified enters the device through an inlet passage48 and chamber 40 and the purified fluid leaves through the external chaml 3' her 44 and outlet passage 50. The arrangement of the various chambers and elements contained therein is claimed in U.S. Patent No. 2,707,563, dated May 3, 1955, common assignee with this application. Element 42 has a rigid core 51 which may be constructed of expanded metal, as shown, or other perforate material, around which is wound a plurality of layers 52 of the nylon-resin material described in the preceding paragraph. This material functions principally as a demulsifying element to cause droplets of the contaminating fluid, which may be water, for example, to form from the moisture entrained in the continuous phase being purified, which may be fuel. These droplets then coalesce and descend to a sump 53 in the bottom of the device and the purified fuel passes through filter elements and leaves the unit through an outlet.

The nylon-resin material of the filter element is encased in a filter section 54 consisting of pleated paper treated with a thermosetting resin, which filters the fluid to eliminate a large percentage of the solid particles and gum from the fiuid before it enters the nylon-resin material and thereby greatly extends the efiective life of the said material. The filter section and nylon-resin material are sealed at their ends by end plates 56 and 58, end plate 58 containing a hole 60 to connect the hollow interior of the element with port 47 and thus with an external chamber.

It has been found that the effectiveness of the nylonresin material as a demulsifying agent can be greatly enhanced by splitting the sheet of material before it is wound around the core. Splitting the material produces a rather fuzzy surface 53 on one side thereof, as shown in Figure 4, which then contacts the smoother surface 55 of the preceding or following convolution. The outer surfaces of each sheet of nylon-resin material contain a larger percentage of resin. When two of these surfaces contact each other, the resistance to flow increases and the life of the demulsifier element is decreased. A method of making the material consists in forming a sheet of nylon fibers, treating the sheet with a resinous material such as phenolic condensation product, splitting the sheet so formed by pulling the sheet apart edgewise, as shown in Figure 5, by means of-a knife-edged 62 and a pair of rollers 64 which may move apart as the material winds there around, and then stacking or otherwise assembling the split sheets into layers to form a structure as shown at 32 in Figure 1 or at 52 in Figures 2 and 3. Although a single sheet or layer can be used satisfactorily for certain filtering operations, it is usually desirable to have a plurality of layers.

While only two illustrations of my invention are disclosed herein, additional modifications and changes may be made without departing from the scope of the invention.

I claim:

1. In a filter, the combination of an inner element formed of layers of nylon resin fibrous material having one side which is relatively loosely packed and another side which is more tightly packed, said material being arranged in said layers so that the loosely packed side of each layer contacts the more tightly packed side of the adjacent layer, and resin impregnated paper filter material surrounding said inner element.

2. In a compound filter element, an inner filtering member comprising a plurality of layers of resin-impregnated nylon fibrous material having one side which is much more loosely packed than the other side, said material being arranged in said layers so that the loosely packed side of each layer contacts the more tightly packed side of the adjacent layer, and an outer filtering member of resin-impregnated paper surrounding said fibrous material.

3. A filter element comprising layers of resin-impreg nated nylon fibrous material having one side which is much more loosely packed than the other side, said mate- 4 rial being arranged in said layers so that the loosely packed side of each layer contacts the more tightly packed side of the adjacent layer.

4. A filter unit for use in filtering gaseous fluids comprising means for mounting said unit on an external member, a metal deflector cap and a filter element positioned within said cap, means for attaching said cap and said filter element to said mounting means, said filter element comprising a conical screen adjacent said mounting means, a plurality of stacked nylon fibrous discs, and a cylindrical edge-type element surrounding said screen and said discs.

5. A filter structure for use in a breather-filler cap assembly comprising a vented plate and means for attaching said plate to an external member, a conical screen adjacent said vented plate, a stack of annular nylon fibrous discs, a cylindrical edge-type element surrounding said screen and said discs, a metal deflector covering a substantial portion of said element, and a threaded member passing through the center of said discs, said deflector, and said vented plate for fastening said assembly together.

6. A filter structure for use in a breather-filler cap assembly comprising a vented plate and means for attaching said plate to an inlet pipe, a conical screen adjacent said vented plate, a stack of annular nylon fibrous discs adjacent said screen, a cylindrical edge-type element surrounding said screen and said discs, a cupshaped air deflector enclosing a substantial portion of said edge-type element, and means for fastening said assembly together.

7. A filter structure as set forth in claim 6 whereinsaid nylon fibrous discs are cut from material which has been split edgewise to produce a mat having one side which is much more loosely packed than the other side.

8. An apparatus for removing contaminants from a liquid comprising an outer casing, an inner casing spaced has been split edgewise to produce a mat having oneside which is more loosely packed than the other, said material being wrapped around said corev and arranged in said layers so that the loosely packed side of each layer contacts the more tightly packed side of the adjacent layer, and a pleated resin-impregnated filter element surrounding said demulsifier element, an annular shelf attached to the interior sidewall of said outer casing, and a plurality of filter elements attached to said shelf in communication with said liquid outlet passage.

9. A method of making a filter element comprising splitting a sheet of nylon fibrous material edgewise to form a mat having one side which is much more loosely packed than the other side, cutting said split sheets into annular washer-like sections, and assembling said sections axially to form a cylindrical unit.

10. A method of making a filter element as set forth in claim 9 wherein said cylindrical unit is assembled within' the hollow interior of a cylindrical edge-type unit.

11. A device for separating liquid and solid contami- "nants from a liquid comprising a casing having a fluid inlet passage and a fiuid outlet passage, a filter-demulsifier elementin said casing including a perforated core, a plurality of layers of nylon-resin material wrapped around said core, said material having one side which is more loosely packed than the other side and being arranged insaid layers so that the loosely packed side of each layer contacts the more tightly packed side of the adjacent layer, and a pleated resin-impregnated filter element surrounding said demuisifier element.

12. A filter-demulsifier element comprising a perforated core, a plurality of layers of nylon-resin material wrapped around said core, said material having one side which is more loosely packed than the other side and being arranged in said layers so that the loosely packed side of each layer contacts the more tightly packed side of the adjacent layer.

1,893,048 Birkholz Jan. 3, 1933 6 Cooper Apr. 13, Arnold .L Apr. 9, Lahherberg May 21, Lowther -2 Dec. 23, Winslow Apr. 4, Himmell Ian. 23, Anderson I an. 30, Fn'cke Sept. 9, Osborne Jan. 20, Curtis Mar. 2, Kasten et a1. May 3, Cunningham Nov. 29, 

